1. Field
The present disclosure concept relates to an electro-photographic photoreceptor (hereinafter, referred to as a photoreceptor) that is used in an electro-photographic image forming apparatus (for example, a fax machine, a copying machine, a laser printer, a CRT printer, a LED printer, a liquid crystal printer, or the like). Also, the present general inventive concept relates to an image forming apparatus including a photoreceptor.
2. Description of the Related Art
A photoreceptor includes a conductive support, and a photoreceptor layer formed on the conductive support.
A photoreceptor layer is largely classified as a stack-type photoreceptor layer and a single layer-type photoreceptor layer. The stack-type photoreceptor layer includes: a charge generation layer including a binder resin and a charge-generating material (CGM); and a charge transport layer including a binder resin and a charge-transporting material (CTM, for example, a hole-transporting material). The stack-type photoreceptor layer is applied to a negative charge-type photoreceptor. The single layer-type photoreceptor layer includes a binder resin, a CGM, and a CTM, which are all included in a single layer, and is applied to a positive charge-type photoreceptor.
In an electro-photographic image forming apparatus, an electrostatic latent image is formed on the surface of a photoreceptor, toner is attached to the electrostatic latent image, which is then developed into a toner image. The toner image on the surface of the photoreceptor is transferred onto a sheet of paper. The residual toner that remains on the surface of the photoreceptor and not transferred is removed from the surface of the photoreceptor by a blade formed of a rubber material.
FIG. 1 is an example of the configuration of a photoreceptor 100 and a blade 200. The blade 200 formed of planar rubber or synthetic rubber is fixed on a rigid blade support 300. The photoreceptor 100 and the blade 200 contact each other at a predetermined angle. When the angle between the photoreceptor 100 and the blade 200, that is, a cleaning angle θ, increases, the residual ink or toner may be more easily removed. However, when the cleaning angle θ exceeds a certain range, the blade 200 may overturn, deform, or vibrate, leading to failing to remove toner.
Conventionally, the cleaning angle is determined by trial and error to prevent the overturning and vibrating of a blade. Also, conventionally, when a photoreceptor is manufactured, a frictional force on the surface of the photoreceptor is not considered, and only photoreceiving characteristics and abrasive characteristics are taken into consideration. Most conventional photoreceptors have a surface frictional force of 100 gf or more, which is measured by a surface friction measurement apparatus illustrated in FIG. 2, although some of them have a surface frictional force of less than 30 gf.